The objectives of this project are to identify and describe environmental and host determinants of cancer in areas of the U.S. at high risk of cancer through the use of analytical epidemiologic techniques, particularly case-control studies of specific cancers. Completed during the year were interview studies of (a) respiratory tumors in Tidewater, Virginia, which showed a 70% smoking-adjusted excess of lung cancer and a 1500% increase of mesothelioma associated with employment, primarily during World War II, in area shipyards; (b) esophageal cancer among black males in Washington, D.C., which revealed a dominating effect of alcohol consumption, although other interesting nutritional differences were also uncovered; and (c) colorectal cancer in rural Nebraska which identified an increased risk among persons of Czechoslovakian descent and a familial clustering. Also completed was a death certificate review of lung and pancreatic cancer in Louisiana; results indicated an excess of petroleum industry occupations associated with both of the cancers and shipbuilding employment associated with lung cancer and a higher frequency of lung cancer among the older Acadian (Cajun) minority.